A new quantum physics experiment just lent evidence to a mind-boggling idea that was previously limited to the realm of theory, according to the MIT Technology Review — that under the right conditions, two people can observe the same event, see two different things happen, and both be correct.

According to research shared to the preprint server arXiv on Tuesday, physicists from Heriot-Watt University demonstrated for the first time how two people can experience different realities by recreating a classic quantum physics thought experiment.

The experiment involves two people observing a single photon, the smallest quantifiable unit of light that can act as either a particle or a wave under different conditions.